"This will be with us for the rest of our lives," he said. "Grace was a beautiful, talented, loving daughter. Grace was our sunshine and she will be missed forever."
Millane's parents sat through every day of the nearly three week-long trial but will not be at the today's hearing in person.
They tearfully told journalists after the guilty verdict they would return to England and "try to pick up the pieces of our lives".
Members of the Auckland police team which worked on the investigation are expected to be at the proceeding today, specifically the three officers who spent the most time with Millane's family; Detective Inspector Scott Beard, Detective Senior Sergeant Greg Brand and Detective Toni Jordan.
Meanwhile, a woman who dated the killer before he murdered Millane said she was glad she spoke to police about the "coward".
"I think justice has been served - we got a guilty verdict.
"We have waited a long time for this," she said of the sentencing.
But there was no sympathy for the killer's likely lengthy prison time.
He was a "coward for taking another girl's life", she explained.
Millane, who was travelling the world, met her killer on the dating app Tinder before they shared some drinks at a few bars on the eve of her 22nd birthday in December 2018.
CCTV showed the pair appeared to be enjoying each other's company as they returned to his small downtown Auckland apartment.
The university graduate would never leave the room alive - her body later found dumped in shallow grave in the Waitākere Ranges.
"I am relieved I could stand up for myself, it could've been me. We did our part by going to the police and we were listened to," the women, who came forward to police after the killer's arrest, said.
"We have processed our hurt and anger but nothing we say will bring Grace back ... I feel for Grace's family they still have a lot of grief to process."
After hearing from nearly 40 witnesses during the highly-charged and emotional trial, the jury's decision was unanimous.
Some jurors broke down and sobbed as they left the courtroom after delivering their guilty verdict.
They heard how the killer strangled Millane to death in his CityLife hotel room and then took "trophy" photos of her body.
He "eroticised the death of British backpacker Grace Millane" because of his "morbid sexual interest", Auckland's Crown Solicitor Brian Dickey told them.
Police used some of the six terabytes of CCTV footage they collected to track the killer's movements across Auckland before and after he killed Millane.
His internet search history, expert witness, and those who knew the murderer's inclination to dominate women was also canvassed.
The killer's defence, led by barrister Ian Brookie, used expert evidence and those who knew Millane to argue it was an accidental death during erotic asphyxiation.
Brookie said his client had "freaked out" before later lying to police and trying to cover up the homicide.